JP3509221B2 - Recording / reproducing device for disk-shaped recording media - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording / reproducing of recorded data by rotationally driving a disk-shaped recording medium such as an optical disk, a magneto-optical disk, a magnetic disk (including a hard disk) at a constant angular velocity. A recording / reproducing apparatus for a disk-shaped recording medium, in which a recording / reproducing area is divided into a plurality of recording / reproducing positions (zones), and a phase of a channel clock is variably controlled according to the zones to record / reproduce recorded data, and particularly, By switching the timing of channel clock phase matching between time and playback,
The present invention relates to a recording / reproducing apparatus for a disk-shaped recording medium, which prevents the inconvenience that recorded data is deviated from a predetermined recording position due to circuit delay or the like.

[0002]

2. Description of the Related Art At present, since a large amount of information can be semi-permanently stored, it is used as a recording medium for the information.
Optical disks are widely used. Known examples of this optical disk include a so-called compact disk (CD) that records desired information as pits, and a magneto-optical disk that records desired information on a photo-magnetization film formed on the disk by using light and magnetism. Has been.

When recording desired information on the optical disk, desired information is sampled to form recording data, and the recording data is recorded on the optical disk. Further, when reproducing the recording data, the recording signal read from the optical disc is sampled and reproduced, and the reproduction data is output. Therefore, in order to make the recorded data to be recorded and the reproduced data to be reproduced accurate, it is necessary to make the phase of the channel clock used for data processing at the time of recording / reproduction accurate.

Here, conventionally, as shown in FIG. 15, there is known a magneto-optical disk recording / reproducing apparatus for recording / reproducing recorded data while rotating the magneto-optical disk 100 by a spindle motor 102 at a constant angular velocity. .

The magneto-optical disk 100 is provided with servo areas at predetermined intervals as shown in FIG. In this servo area, there are clock pits 201 formed on the recording track (TR), and the clock pits 201 are deviated to the inner and outer circumference sides with respect to the recording track at predetermined intervals on both sides. A servo pattern including a pair of wobble pits 200 formed as described above is recorded.

A recording / reproducing apparatus for recording / reproducing on / from the magneto-optical disk 100 as described above, before recording / reproducing recorded data, forms a servo pattern for forming a channel clock having an accurate phase based on the detection output of the servo pattern. The detection mode is set.

In the servo pattern detection mode, the recording / reproducing apparatus rotationally drives the magneto-optical disk 100 at a constant angular velocity by the spindle motor 102 and scans the magneto-optical disk 100 by the optical system 103. As described above, the clock pit 201 is formed on the recording track TR, and the wobble pit 20 is formed.
0 is formed by deviating from the recording track TR by a predetermined amount. Therefore, when the above-mentioned scanning is performed on the just track, as shown in FIG. 17, the reproduction waveform of the wobble pit 200 of slightly low level exists on both sides of the reproduction waveform of the clock pit 200 as the center. A reproduced signal of the servo pattern having such a reproduced waveform is formed.

The reproduced signal of this servo pattern is R / W.
The signal is amplified by the amplifier 104 with a predetermined gain and supplied to the A / D converter 105 in the channel clock forming circuit 101.

The A / D converter 105 is supplied with a basic clock having a free-running frequency from a first voltage variable oscillator (VCO) 113 described later. Above A / D
The converter 105 forms reproduction data by sampling and digitizing the reproduction signal based on the basic clock, and forms the reproduction data, which is then read by the servo pattern detection circuit 109.
And the data latch circuit 10 in the phase error detection circuit 106.
Supply to 7.

In the servo pattern detection circuit 109,
The servo pattern is stored in advance. The servo pattern detection circuit 109 detects the servo pattern in the reproduction data by comparing the previously stored servo pattern with the reproduction data, and outputs the servo pattern detection data to the timing generator 110. Supply.

The basic clock from the first VCO 113 is supplied to the timing generator 110, and the basic clock is counted. The timing generator 110 clears the count value when the servo pattern detection data is supplied, and starts counting the basic clock again. Then, when this count value reaches a predetermined value, that is,
The data latch circuit 107 supplies a data latch pulse to the data latch circuit 107 at a timing such that the servo pattern in the reproduced data can be latched.

The data latch circuit 107 latches the reproduced data of the servo pattern by the data latch pulse as shown in FIG.
Latch data b0 to b2 of the wobble pit 200
Latch data a0-a2, c0-c2, and latch data d0 of the mirror area which is an area in which no data is recorded between the servo pattern and the data segment shown in FIG. Supply to 108.

Since the waveforms of the reproduced data of the pair of wobble pits 200 and the clock pits 201 are symmetrical to each other, the phase error forming circuit 108 latches data at the center point of the waveforms a0 in FIG. Point, b0
In the figure, a1 points, a2 points, b1 points, b2 points, which are latch data of both shoulders, one basic clock before and after the point, c0 point
Based on the level difference between the points c1 and c2, the phase error of the basic clock with respect to the reproduction data of the servo pattern is detected by the following equation 1, and this is supplied to the D / A converter 111 as phase error detection data. .

Phase error data = [(a2-a1) + (c2-c1)] / 2 ... Equation 1 Incidentally, the latch data a0 to a2 of the servo pattern
Although not shown, b0 to b2, c0 to c2, and latch data d0 in the mirror area are calculated from the center of the track and the formation of the tracking error signal by the arithmetic expressions shown in the following Expressions 2 to 6 performed by each unit. Within ± 1/4, that is, when a half of the sum of a0 and c0 becomes smaller than b0, a tracking polarity signal (TPOL) which is a high level signal is formed, and ± 1/8 track or more from the track center When it is deviated, that is, when the level of a0 or c0 becomes higher than the level of b0, a 1/8 off-track signal that is a high level signal is formed, a wobble pit average level detection signal is formed, and the mirror is formed. It is used for forming a level detection signal for a region.

Tracking error signal = c0−a0 ... Equation 2 1/8 Off-track signal = [(b0 <a0) ∨ (b0 <c0)] ... Equation 3 TPOL = b0> [(a0 + c0) / 2 ] Equation 4 Wobble pit average level detection signal = (a0 + c0) / 2 ... Equation 5 Mirror area level detection signal = d0 Equation 6 The D / A converter 111 detects the phase error. The data is converted into an analog signal to form a phase error detection signal, which is supplied to the phase compensation circuit 112.

The phase compensating circuit 112 is composed of, for example, a low-pass filter or the like, removes high-frequency noise components and the like of the phase error detection signal to perform phase compensation of the phase error detection signal, and the phase compensation circuit 112 performs the phase compensation of the phase error detection signal. 1 to the VCO 113.

The VCO 113 changes the phase of the basic clock to be output according to the phase error detection signal, and changes the phase of the basic clock to be output by the A / D converter 107 and the timing generator 11.
Return to 0.

As described above, the portion of the recording / reproducing apparatus for the magneto-optical disk that forms the basic clock has a so-called phase-locked loop (PLL) configuration, and the phase of the reproduction data of the servo pattern is set. It is designed to output a basic clock with a synchronized phase.

When the recording / reproducing apparatus for the magneto-optical disk can output the basic clock having a phase synchronized with the phase of the reproduced data of the servo pattern (when the pulling in of the phase of the reproduced data of the servo pattern is completed),
This servo pattern detection mode is ended, and a standby state for recording or reproducing recorded data is set.

Next, the recording / reproducing apparatus for the magneto-optical disk enters the recording mode when the recording of the recording data is designated in the standby state.

Here, since the magneto-optical disk 100 is rotationally driven at a constant angular velocity, if recording and reproduction are performed using the basic clock formed based on the reproduction signal obtained at each predetermined rotation angle, the outer circumference is obtained. There is a problem that the recording density becomes lower as the recording track becomes closer to the side, and the utilization efficiency of the recording area deteriorates.

Therefore, the recording / reproducing apparatus for the magneto-optical disk has nine recording / reproducing areas (zone 0 to zone 8) from the outer peripheral side to the inner peripheral side of the recording / reproducing area of the magneto-optical disk 100 as shown in FIG. The recording data is recorded and reproduced by forming a channel clock having a phase corresponding to this zone.

That is, when the recording / reproducing apparatus for the magneto-optical disk is in the recording mode, the first VCO 1
The basic clock from 13 is supplied to the 1/24 frequency divider circuit 114. The 1/24 frequency dividing circuit 114 divides the frequency of the basic clock by 24 and supplies it to the phase comparator 115.

On the other hand, in the recording mode, the processor 119 detects the zone on the magneto-optical disk 100 for recording the recording data and supplies the zone detection output to the zone setting register 120. The zone setting register 120 sets the zone number corresponding to the zone detection output from the processor 119 to the N division ratio setting circuit 12
Set to 1. The N frequency division ratio setting circuit 121 divides the frequency of the 1 / N frequency dividing circuit 118 to which the channel clock from the second VCO 117 described later is supplied according to the zone number set by the zone setting register 120. Set the ratio to 24-48. 1 / N frequency divider circuit 1
Reference numeral 18 divides the channel clock by the division ratio set by the N division ratio setting circuit 121, and supplies this to the phase comparator 115.

Specifically, since the frequency division ratio of the 1 / N frequency dividing circuit 118 is set to 24 to 48 in accordance with the zone, the phase comparator 115 is multiplied by the basic clock. The channel clock multiplied by 2 times is supplied according to the zone.

The phase comparator 115 has the basic clock divided by 24 from the 1/24 frequency divider circuit 114 and the N frequency divided by the 1 / N frequency divider circuit 118 (24 to 48).
The phase error with the divided frequency is detected, and this phase error data is low pass filter (LPF).
It is supplied to the second VCO 117 via 116. The second VCO 117 forms a channel clock having a phase corresponding to the phase error data and modulates the channel clock.
Supply to.

The modulator circuit 125 includes an input terminal 124.
Recording data is supplied via. The modulation circuit 1
25 performs a predetermined modulation process suitable for recording on the recording data based on the channel clock from the second VCO 117, and supplies this to the driver 126. The driver 126 drives the magnetic head 127 according to the modulated recording data. As a result, a magnetic field corresponding to the recording data is generated via the magnetic head 127 and applied to the magneto-optical disk 100.

A recording level laser beam from the optical system 103 is applied to the applied portion of the magneto-optical disk 100 and is heated to a so-called Curie temperature. Therefore, the portion irradiated with the laser beam is magnetized in accordance with the magnetic field applied via the magnetic head 127, and the recording data is recorded.

As described above, the channel clock has a phase corresponding to the zone in which the recording data is recorded. Therefore, even if the magneto-optical disk 100 is rotationally driven at a constant angular velocity to record the recording data, the recording density on the outer circumference side and the inner circumference side can be made substantially constant.
The utilization efficiency of the recording area of the magneto-optical disk 100 can be improved.

Next, when the reproduction of the recorded data recorded in this way is designated, the recording / reproducing apparatus for the magneto-optical disk enters the reproducing mode.

In this reproducing mode, a channel clock having a phase corresponding to the zone in which the recorded data is reproduced is formed and supplied to the demodulation circuit 122 as in the recording mode.

The demodulation circuit 122 includes the optical system 10 described above.
The reproduction signal reproduced by 3 is supplied via the R / W amplifier 104. The demodulation circuit 122 performs a predetermined demodulation process on the reproduced signal based on the channel clock and supplies the demodulated signal to a speaker device or the like via an output terminal 123. As a result, it is possible to obtain an audio output according to the reproduction signal reproduced from the magneto-optical disc 100 via the speaker device.

As described above, the channel clock supplied to the demodulation circuit 122 is a channel clock having a phase corresponding to the zone in which the recorded data is reproduced. Therefore, the reproduction data can be accurately demodulated according to the zone, and an accurate sound output can be obtained through the speaker device.

[0034]

However, since the recording / reproducing apparatus for the magneto-optical disk described above is designed to perform recording and reproducing at a timing when a predetermined time has elapsed after the servo pattern was detected, the recording / reproducing operation is performed at a predetermined time during the recording. However, there is a problem that the data is recorded at a position deviated from the data recording area.

That is, by the time the reproduction data of the servo pattern reproduced by the optical system 103 is supplied to the servo pattern detection circuit 109, the optical system 10 will be described.
3 to a delay of an analog processing system filter including the A / D converter 105 and the integrated circuit itself, and the A / D converter 1
It takes several tens to several hundreds of nsec depending on the conversion time of 05. Therefore, the servo pattern detection circuit 109
In the above, the time at which the servo pattern is detected is several tens to several hundreds with respect to the time when the servo pattern is actually reproduced from the magneto-optical disk 100 (with respect to the actual recording position on the disk plate surface). This means that there is a delay of nsec. Therefore, at the time of reproduction, there is no problem because the reading may be started after a predetermined time has elapsed from the detection of the servo pattern, but when recording is started at the same timing as the time of reproduction, the above-mentioned delay causes
This causes an inconvenience that recording is performed with a delay from the writing start position of the data recording area.

The present invention has been made in view of the above-mentioned problems. Due to the delay of the analog processing system or the like, the timing at which the servo pattern is detected is delayed with respect to the actual recording position on the disk plate surface. It is an object of the present invention to provide a recording / reproducing apparatus for a disk-shaped recording medium, which can start recording of recording data from the writing start position of the data recording area even when the recording is generated.

[0037]

SUMMARY OF THE INVENTION A recording / reproducing apparatus for a disk-shaped recording medium according to the present invention forms a servo pattern periodically recorded on a disk-shaped recording medium which is rotationally driven at a constant angular velocity.
Reproduction optical system and reproduction of the servo pattern reproduced above
Servo pattern detection that detects the servo pattern from the signal
Means, a basic clock forming means of a phase locked loop configuration for forming a basic clock synchronized with the detection output of the servo pattern, and a servo pattern detection output detected by the basic clock forming means at the time of reproducing recorded information. Based on the above, a reproduction timing control signal indicating a predetermined reproduction start timing is formed and output, and at the time of recording the recording information, the reproduced servo pattern reproduction signal is based on the detected output of the servo pattern.
For the time required to supply to the pattern detection means ,
Timing control means for forming and outputting a recording timing control signal for advancing the recording start timing, and variably controlling the phase of the basic clock from the basic clock forming means according to the recording / reproducing position of the disc-shaped recording medium. At the same time, the phase of the basic clock is variably controlled according to the reproduction timing control signal or the recording timing control signal, and this is output as a channel clock. Recording / reproducing means for recording / reproducing recording information on / from the disc-shaped recording medium based on a channel clock from the means.

Further, in the recording / reproducing apparatus for the disk-shaped recording medium according to the present invention, a delay means for delaying the basic clock from the basic clock forming means by a fixed amount of one basic clock or less, and the basic clock for reproducing are provided. It has a selecting means for selecting a basic clock from the forming means and supplying it to the channel clock forming means, and a recording means for selecting the basic clock from the delay means and supplying it to the channel clock forming means.

Alternatively, in the recording / reproducing apparatus for the disk-shaped recording medium according to the present invention, the basic clock from the basic clock forming means is delayed by an arbitrary amount of one basic clock or less and supplied to the channel clock forming means. It has a delaying means.

Specifically, in the disc-shaped recording medium recording / reproducing apparatus according to the present invention, as the delay means, a ring oscillator for applying a plurality of kinds of delays of one basic clock or less to the basic clock and outputting the ring oscillator, It has a selecting means for selecting a basic clock having a desired phase from a plurality of basic clocks having a plurality of types of phases from the ring oscillator and supplying the basic clock to the channel clock forming means.

[0041]

A disk recording medium recording / reproducing apparatus according to the present invention uses an optical system for reproducing a servo pattern periodically recorded on a disk recording medium which is rotationally driven at a constant angular velocity .
The servo pattern reproduced signal reproduced from the
Based on the detection output of the servo pattern by the servo pattern detection means for detecting the servo signal, a basic clock synchronized with the detection output of the servo pattern is formed, and the phase of this basic clock is set to the recording / reproducing position on the disc-shaped recording medium. In accordance with the above, the channel clock is formed by performing variable control, and the recording information is recorded / reproduced based on this channel clock.

Here, it takes, for example, several tens to several hundreds of nsec from the reproduction of the servo pattern on the disk-shaped recording medium to the detection thereof. Therefore, if the recording information is recorded at the timing at which the servo pattern is detected, the recording is started after a predetermined recording position, and the recording information is recorded with a deviation from the predetermined recording position. Occurs.

Therefore, at the time of reproducing the recorded information, the timing control means forms a reproduction timing control signal indicating a predetermined reproduction start timing based on the detection output of the servo pattern detected by the basic clock forming means. Although it outputs, at the time of recording the recording information, based on the detection output of the servo pattern, a recording timing control signal for advancing the recording start timing by the time required from the reproduction to the detection of the servo pattern is formed, This is supplied to the channel clock forming means.

The channel clock forming means variably controls the phase of the basic clock according to the recording timing control signal and supplies it to the recording / reproducing means.

With this, it is possible to accurately start recording from a predetermined recording position on the disc-shaped recording medium, and it is possible to prevent the inconvenience that the recording information is recorded with a deviation from the predetermined recording position.

Next, since the phase of the channel clock is controlled on the basis of the phase of the basic clock, the phase control cannot be performed with an accuracy of one basic clock or less. Therefore, in the recording / reproducing apparatus for the disk-shaped recording medium according to the present invention, the delay means delays the basic clock from the basic clock forming means by a fixed amount of one basic clock or less and supplies it to the selecting means. The selecting means selects the basic clock from the basic clock forming means and supplies it to the channel clock forming means at the time of reproduction, and selects the basic clock from the delay means at the time of recording to the channel clock forming means. Supply.

As a result, the phase accuracy of the channel clock formed by the channel clock forming means can be set to an accuracy of one basic clock or less, and more accurate recording / reproducing can be performed.

Alternatively, in the recording / reproducing apparatus for a disk-shaped recording medium according to the present invention, the delay means delays the basic clock from the basic clock forming means by an arbitrary amount of one basic clock or less, and then the channel clock. Supply to the forming means.

Specifically, the delay means includes a ring oscillator that outputs a plurality of types of delays of one basic clock or less to the basic clock, and a plurality of basic clocks having a plurality of types of phases from the ring oscillator. Selection means for selecting a basic clock having a desired phase from among the above and supplying it to the channel clock forming means. Therefore, the phase accuracy of the channel clock formed by the channel clock forming means can be set to the accuracy of the resolution of the ring oscillator, and more accurate recording / reproducing can be performed.

Further, the basic clock having a desired phase is selected from the plurality of phases formed by the ring oscillator in this way, and the channel clock is formed based on the phase of the basic clock. After the servo pattern on the disk-shaped recording medium is reproduced, the reproduced servo pattern reproduction signal is the servo pattern.
Even if there is a variation in each device during the time until it is supplied to the sensor detection means , this can be corrected and accurate recording / reproduction can be performed.

[0051]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a recording / reproducing apparatus for a disk-shaped recording medium according to the present invention will be described in detail below with reference to the drawings.

The recording / reproducing apparatus for a disk-shaped recording medium according to the present invention is applied to a magneto-optical disk recording / reproducing apparatus for recording / reproducing recorded data by rotationally driving a magneto-optical disk 1 at a constant angular velocity as shown in FIG. can do.

In FIG. 1, the magneto-optical disk recording / reproducing apparatus according to the first embodiment comprises a channel clock forming section 2 surrounded by a dotted line in the drawing and a reproducing system 3 surrounded by a dashed line in the drawing. , Recording system 4 surrounded by a chain double-dashed line in the figure
It consists of and.

This magneto-optical disk recording / reproducing apparatus variably controls the phase of the channel clock formed by the channel clock forming section 2 according to the recording / reproducing position (zone) on the magneto-optical disk 1. Correspondingly, the recording / reproducing area of the magneto-optical disc 1 is divided into, for example, 15 zones in the radial direction of the disc as shown in FIG.

The magneto-optical disk 1 is provided with servo areas (Servo Areas) as shown in FIG. In each servo area, a segment mark SM formed in the center of a recording track TR formed concentrically, and a predetermined amount of transition from the center of the recording track TR to the inner peripheral side and the outer peripheral side subsequent to the segment mark SM are formed. Servo patterns each consisting of a pair of wobble pits WP formed in this way are recorded. It should be noted that this servo pattern is previously recorded as a prepit.

Areas other than the servo area of the magneto-optical disk 1 are data areas, and synchronous data, address data, recording data, etc. are alternately arranged in this data area by utilizing the magneto-optical effect. Recorded,
Recording / playback management of recording data is performed based on the synchronization data and address data.

The reproducing system 3 irradiates the magneto-optical disk 1 with a spindle motor 5 which rotates and drives the magneto-optical disk 1 at a constant angular velocity, and irradiates the magneto-optical disk 1 with a weak level laser beam for reproduction and reproduces the reflected light. An optical system 9 for reproducing the servo pattern, the recorded data, etc., and an R / W amplifier circuit (R / W amplifier) 10 for amplifying and outputting a reproduction signal reproduced by the optical system 9 with a predetermined gain. A channel clock forming unit 2 that forms a channel clock whose phase is varied for each zone based on the reproduction data of the servo pattern, and a predetermined demodulation process for the reproduction signal reproduced by the optical system 9 based on the channel clock. And a demodulation circuit 11 for performing.

The recording system 4 includes the spindle motor 5
An optical system 9 for irradiating the magneto-optical disc 1 with a strong laser beam for recording during recording and reproducing the servo pattern based on the reflected light; the R / W amplifier 10; A channel clock forming unit 2 that forms a channel clock, a modulation circuit 6 that performs a predetermined modulation process on the recording data based on the channel clock, and a recording head 7 that drives the recording data from the modulation circuit 6. It is composed of a driver 8 and a magnetic head 7 for applying a magnetic field according to the recording data to a portion irradiated with the recording laser beam.

The channel clock forming unit 2 is A /
D converter 20 to first voltage variable control oscillator (first V
A first phase-locked loop circuit (PLL circuit) which is formed of a CO) 32 and forms a basic clock of a predetermined phase which is a sampling clock of the A / D converter 20 and the 1/24 frequency divider circuit 33. ~ Central processing unit (C
PU) 40, which forms a channel clock in which the phase of the basic clock is variably controlled to a phase corresponding to the zone on the magneto-optical disk 1, and a basic clock for recording and reproducing. And a phase comparison timing generator 41 and a phase comparison timing generation register 42 for controlling the timing of phase comparison of the channel clocks.

Next, the operation of the magneto-optical disk recording / reproducing apparatus according to the first embodiment having such a structure will be described.

First, in the magneto-optical disk recording / reproducing apparatus, prior to the recording / reproducing of the recorded data, in the channel clock forming section 2, the servo of the phase of the detection data of the servo pattern and the phase of the basic clock are adjusted. The pattern detection mode is set. That is, since the servo pattern is not unique to a normal data pattern, the periodicity of the servo pattern is used to perform the pull-in operation of the first PLL circuit of the channel clock forming unit 2.

In this servo pattern detection mode,
The magneto-optical disc recording / reproducing apparatus rotationally drives the magneto-optical disc 1 at a constant angular velocity via the spindle motor 5. The optical system 9 irradiates the magneto-optical disk 1 driven to rotate with a weak laser beam for reproduction and detects the reflected light. Then, by photoelectrically converting the reflected light, the servo pattern or the like recorded on the magneto-optical disk 1 is reproduced, and the reproduced signal is reproduced by R
It is supplied to the A / D converter 20 via the / W amplifier 10.
The A / D converter 20 has a first VCO described later.
A basic clock as shown in FIG. 5A is supplied from 32. The A / D converter 20 forms reproduction data by sampling and digitizing the reproduction signal based on the basic clock, and supplies the reproduction data to the data latch circuit 22 in the phase data forming circuit 21. Servo pattern detector 2 via pulse detector 24
Supply to 5.

Data of the same pattern as the servo pattern formed on the magneto-optical disk 1 is previously stored in the servo pattern detector 25. The servo pattern detector 25 compares the data of the same pattern as the previously stored servo pattern with the reproduction data of the servo pattern, and when the servo pattern is detected, the servo pattern detection pulse becomes high level, for example. Is supplied to the counter 26 and the lock / unlock detection circuit 27.

The counter 26 is provided with the first VCO.
The basic clock from 32 is supplied. The counter 26 resets the count value by using the servo pattern detection pulse as a trigger. Then, the basic clock is newly counted from the reset time. Specifically, if the basic clock output from the first VCO 35 has an accurate phase, after the high level servo pattern detection pulse is supplied to the lock / unlock detection circuit 27, the next high level is output. The time until the servo pattern detection pulse is supplied is, for example, 216 basic clocks. Therefore, the counter 26 forms a first window pulse when the count value of the basic clock reaches 216, and supplies this to the lock / unlock detection circuit 27.

The lock / unlock detection circuit 27 is
When a high level servo pattern detection pulse is supplied from the servo pattern detector 25 when the first window pulse is supplied, a high level pulse as shown in FIG. Supply to.

When the high level pulse is supplied from the lock / unlock detection circuit 27, the intra-segment counter 28 resets the count value, and like the counter 26, the counter V from the first VCO 32 is reset from here. 216 basic clocks are counted. Then, this count value is supplied to the timing generator 29.

The timing generator 29 detects the count value from the intra-segment counter 28, and this count value should be supplied to the lock / unlock detection circuit 27 as a high-level servo pattern detection pulse. At the time (count value) of 216 counts, a second window pulse is formed and supplied to the lock / unlock detection circuit 27.

The lock / unlock detection circuit 27 is
When the second window pulse is being supplied,
When the high level servo pattern detection pulse is supplied from the servo pattern detector 25, the high level pulse is supplied to the intra-segment counter 28. As a result, the count value of the intra-segment counter 28 is reset, and the above counting operation is performed again.

As described above, since the servo pattern is not unique to the normal data pattern, there is a risk that it will coincide with the data pattern of the reproduced data.
Therefore, assuming that only the counter 26 is provided, when the counter 26 is reset by the reproduction data having the same data pattern as the servo pattern, thereafter,
Servo pattern detection data is output at an incorrect timing, and it becomes impossible to pull in the phase of the servo pattern detection data.

However, this channel clock forming unit 2
, The first first window pulse and the next first window pulse
Is provided with an intra-segment counter 28 that is reset when the servo pattern detection pulse is input twice in succession, and the second counter is formed when the intra-segment counter 28 reaches a predetermined count value. Since the servo pattern detection pulse is formed by the window pulse of, the accurate servo pattern can be detected even if the servo pattern is not a unique pattern.

Here, as shown in FIG. 4, the reproduced waveform of the reproduced data of the servo pattern is the segment pit SM.
And the reproduced waveform of the wobble pit WP having a slightly lower level than the reproduced waveform of the segment pit SM. Therefore, the timing generator 29
Are the vertices a0, c0 and the vertices a0, c0 of the reproduced waveform of the wobble pit WP based on the count value of the basic clock supplied from the intra-segment counter 28.
The latch pulse is formed at the timing of latching the points a1, a2, c1, c2 on both shoulders of c0, and these are supplied to the data latch circuit 22.

As described above, since the servo pattern can be accurately detected by the pulse detector 24 to the intra-segment counter 28, the timing generator 2 can be used.
9 enables the data latch circuit 22 to generate a latch pulse at a timing at which the servo pattern can be accurately latched.

The data latch circuit 22 latches each point a0, a1, a2 and c0, c1, c2 of the reproduced waveform of the wobble pit WP on the basis of the latch pulse, and these latched data is generated by a phase generator. 23.

The phase generator 23 detects the phase error of the basic clock with respect to the reproduced data of the servo pattern by performing the calculation shown in the following formula 7 based on the latch data of each point, and calculates it. The phase error detection data is supplied to the D / A converter 30.

Phase error detection data = [(a2-a1) + (c2-c1)] / 2 ... Equation 7 The reproduction data of this servo pattern is represented by the following Equation 8:
~ Formation of a tracking error signal as shown in Equation 12,
Within ± 1/4 from the track center, that is, a0 and c0
Of the tracking polarity signal (T
POL), formation of a 1/8 off-track signal which is a signal which becomes high level when it deviates from the track center by ± 1/8 track or more, that is, when the level of a0 or c0 becomes larger than the level of b0. , Is used for forming the detection signal of the average level of the wobble pits and for forming the level detection signal of the mirror portion provided between the servo pattern and the data area.

Tracking error signal = c0-a0 ... Equation 8 1/8 Off-track signal = [(b0 <a0) ∨ (b0 <c0)] ... Equation 9 TPOL = [b0> [(a0 + c0) / 2]] ... Equation 10 Wobble pit average level detection signal = (a0 + c0) / 2 ... Equation 11 Mirror level detection signal = d0 ... Equation 12 The D / A converter 30 has the phase A phase error detection signal is formed by analogizing the error detection data and is supplied to the first VCO 32 via the phase compensation circuit 31.

The first VCO 32 forms a basic clock having a phase such that the phase error of the basic clock with respect to the servo pattern detection data indicated by the phase error detection signal becomes zero. It is supplied to the A / D converter 20, the counter 26, and the intra-segment counter 28.

When the pulling in of the phase of the servo pattern detection data is completed in this way, the magneto-optical disk recording / reproducing apparatus ends the servo pattern detecting mode and enters a state of waiting for designation of the recording mode or the reproducing mode.

Next, the operation of the magneto-optical disk recording / reproducing apparatus according to the first embodiment in the recording mode will be described.

First, when the recording of the record data is designated in the designation waiting state, the magneto-optical disc recording / reproducing apparatus enters the recording mode. When in the above recording mode,
The basic clock from the first VCO 33 is supplied to the 1/24 frequency divider circuit 33. 1/24 frequency divider circuit 33
Is 2 by counting the above basic clock by 24
The frequency is divided by 4 and supplied to the phase comparator 34. It should be noted that this 1/24 frequency divider circuit 33 is configured as a counter with synchronization clear in which the count value is reset based on the phase comparison timing signal from the phase comparison timing generator 41 described later.

On the other hand, in this recording mode, the CPU 4
0 detects, for example, a zone in which recording data designated by the user is recorded, and supplies this zone data to the zone setting register 39.

The first zone setting register 39 sets the zone indicated by the zone data by the N division ratio setting circuit 3
Set to 8. The N frequency division ratio setting circuit 38 has a second V
Channel clock from CO36 is supplied 1 / N
The frequency dividing ratio of the frequency dividing circuit 37 is set to 24 to 48 according to the zone set above.

That is, the phase of the channel clock is variably controlled to be 1 to 2 times the phase of the basic clock divided by 24 by the 1/24 divider circuit 33 according to the zone. Become. The 1 / N frequency divider circuit 37
Variably controls the phase of the channel clock from the second VCO 36 according to the zone and supplies it to the phase comparator 34.

The phase comparator 34 has the phase of the basic clock from the 1/24 frequency divider 33 and the phase of the channel clock variably controlled according to the zone from the 1 / N frequency divider 37. And the phase error is detected. Then, this phase error detection signal is supplied to the second VCO 36 via the LPF 35.

As a result, the second VCO 36 outputs the channel clock having the phase corresponding to the zone in which the recording data is recorded. When the magneto-optical disk 1 is rotationally driven at a constant angular velocity to record the recording data, the recording density on the outer peripheral side becomes low, which causes a problem that the recording area cannot be effectively used. By variably controlling the phase of the channel clock according to the zone to be performed, the recording density on the outer peripheral side can be increased, and the recording area can be effectively used.

Here, by the time the reproduction data of the servo pattern reproduced in the optical system 9 is supplied to the servo pattern detection circuit 24, analog processing constituted by the optical system 9 to the A / D converter 20 is performed. For example, 160 nsec is required due to the delay of the system filter and the integrated circuit itself and the conversion time of the A / D converter 20. Therefore, the time at which the servo pattern is detected by the servo pattern detector 24 is the time when the servo pattern is actually reproduced from the magneto-optical disk 1 (with respect to the actual recording position on the disk plate surface). ), For example 16
There is a delay of 0 nsec. This delay is a delay of two basic clocks when the cycle of the basic clock is 80 nsec. Therefore, the timing of starting writing the data on the disk surface and the timing of starting the reading of the data at the time of reproduction are deviated by 2 clocks, and the timing at the time of recording is advanced by 4 clocks from the time at the time of reproduction. It is the timing to start recording on the disk surface.

Therefore, when this recording mode is designated, the CPU 40 supplies recording mode data indicating that the current mode is the recording mode to the phase comparison timing generation register 42.

Assuming that the recording / reproducing area in which the recording data on the magneto-optical disk 1 is recorded / reproduced starts at the timing of 5 with the count value of the intra-segment counter 28, the phase comparison timing generation register 42 causes the CPU 40 to operate. The detection count value of the phase comparison timing generator 41 to which the count value from the intra-segment counter 28 is supplied is set to "2" based on the recording mode data from.

The phase comparison timing generator 41 includes:
As described above, the count value from the intra-segment counter 28 is supplied, and this count value is monitored. Then, at time t1 when the count value becomes a value of "2" set by the phase comparison timing generation register 42 as shown in FIG. 5C, for example, a negative value as shown in FIG. A synchronization clear signal which is a pulse is formed and is supplied to the 1/24 frequency divider circuit 33.

As described above, the 1/24 frequency divider circuit 33 is used.
Is a counter with synchronization clear. When the synchronization clear signal is supplied, the counter clears the count value of the basic clock as shown in FIG. 5E, and, for example, as shown in FIG. The phase comparison signal which is a negative pulse is supplied to the phase comparator 34.

The 1 / N frequency dividing circuit 37 is, for example, the above 1
Assuming that the frequency division ratio is set to 24 by the / N frequency division ratio setting circuit 38, as shown in FIG.
24 channel clocks from CO36 are counted,
As shown in (g) of the figure, when the count value becomes 0, for example, a phase comparison signal which is a negative pulse is supplied to the phase comparator 34.

The phase comparator 34 phase compares the phase comparison signal from the 1/24 frequency divider circuit 33 with the phase comparison signal from the 1 / N frequency divider circuit 37, and according to this phase error, Drive the second VCO 36.

As a result, the phase of the channel clock can be controlled so as to match the recording timing, as shown in FIG. 5 (i). This channel clock is supplied to the modulation circuit 6.

Recording data is supplied to the modulation circuit 6 through the input terminal 12. The modulation circuit 6 performs a predetermined modulation process suitable for recording on the recording data on the basis of the channel clock used as the phase at the time of recording,
This is supplied to the driver 8. The driver 8 drives the magnetic head 7 according to the recording data. The magnetic head 7 applies a modulating magnetic field according to the recording data to the magneto-optical disk 1. A strong laser beam for recording is emitted from the optical system 9 to the portion to which the modulation magnetic field is applied, and the portion to which the laser beam is emitted is
It is heated to the so-called Curie temperature. This allows
A portion irradiated with the laser beam can be magnetized in accordance with the modulation magnetic field in a non-coercive force state, and recording of recording data can be performed.

In the magneto-optical disk recording / reproducing apparatus, the delay of the filter of the analog processing system constituted by the optical system 9 to the A / D converter 20 and the integrated circuit itself, the conversion time of the A / D converter 20, etc. Thus, even if there is a deviation (delay) between the actual recording start position and the recording start timing, the phase comparison timing generator 41 advances the timing of phase comparison between the basic clock and the channel clock by the delay. Can be set to. For this reason,
It is possible to set the recording start timing earlier by the amount of the above delay, and absorb the above delay at the time of actual recording, so that the timing shown in FIG.
As shown in (j), it is possible to accurately start recording the recording data from the recording start position.

Next, when the reproduction of the record data is designated in the designation waiting state, the magneto-optical disc recording / reproducing apparatus is set to the reproducing mode. When the reproduction mode is designated, the CPU 40 supplies reproduction mode data indicating that the current mode is the reproduction mode to the phase comparison timing generation register 42.

As described above, the recording / reproducing area in which the recording data on the magneto-optical disk 1 is recorded / reproduced starts at the timing of 5 with the count value of the intra-segment counter 28. Therefore, the phase comparison timing generation register 4
2 sets the detection count value of the phase comparison timing generator 41 to which the count value is supplied from the intra-segment counter 28 to "4" based on the recording mode data from the CPU 40.

In the phase comparison timing generator 41,
As described above, the count value is supplied from the intra-segment counter 28 that counts the basic clock shown in FIG. 6A by 216 as shown in FIG. 6B, and this count value is monitored. Then, the count value shown in FIG.
As shown in (c), at time t2 when the value of "4" set by the phase comparison timing generation register 42 is reached,
A sync clear signal, which is, for example, a negative pulse as shown in FIG. 7D, is formed and supplied to the 1/24 frequency divider circuit 33.

When the synchronization clear signal is supplied, the 1/24 frequency divider circuit 33 clears the count value of the basic clock as shown in FIG. 6 (e) and also as shown in FIG. 6 (f). Then, a phase comparison signal, which is a negative pulse, is supplied to the phase comparator 34.

The 1 / N frequency divider circuit 37 is, for example,
If the frequency division ratio is set to the frequency division of 24 by the / N frequency division ratio setting circuit 38, as shown in FIG.
24 channel clocks from CO36 are counted,
When the count value becomes 0, a phase comparison signal which is a negative pulse, for example, is supplied to the phase comparator 34 as shown in FIG.

The phase comparator 34 compares the phase comparison signal from the 1/24 frequency divider circuit 33 with the phase comparison signal from the 1 / N frequency divider circuit 37, and according to this phase error, the phase comparator 34 compares the phase comparison signal with the phase comparison signal. Drive the second VCO 36.

As a result, the phase of the channel clock can be controlled so as to match the timing of reproduction, as shown in FIG. 6 (i). This channel clock is supplied to the demodulation circuit 11.

A reproduction signal reproduced by the optical system 9 irradiating the magneto-optical disk 1 with a laser beam of a weak level for reproduction is supplied to the demodulation circuit 11 through the R / W amplifier 10. ing. The demodulation circuit 11 performs a predetermined demodulation process on the reproduction data based on the channel clock from the second VCO 36, and outputs the reproduction signal to an externally connected speaker device or the like via the output terminal 13. Supply. Thus, when audio data is recorded as recording data on the magneto-optical disk 1, an acoustic output corresponding to the audio data can be obtained via the speaker device.

As described above, the phase of the channel clock is controlled so as to be the timing for reproduction. Therefore, as shown in FIG. 6J, it is possible to accurately start the reading of the recording data from the recording start position of the recording data.

As is clear from the above description, in the magneto-optical disk recording / reproducing apparatus according to the first embodiment of the present invention, the basic clock and the channel clock performed by the phase comparator 34 at the time of recording and at the time of reproducing. By controlling the switching of the phase comparison timing of, the recording data can be accurately started from the predetermined recording start position during recording, and the recording data can be accurately recorded from the position where the recording data is recorded during reproduction. Playback can be performed.

Next, if the count value of the 1/24 frequency divider circuit 33 is cleared at the timing of recording and the timing of reproducing, only the control in units of basic clocks can be performed. For this reason, in the magneto-optical disk recording / reproducing apparatus according to the second embodiment of the present invention, the channel clock forming unit 2 is configured as shown in FIG. In the description of the magneto-optical disk recording / reproducing apparatus according to the second embodiment, the same reference numerals are given to the portions showing the same operations as those of the magneto-optical disk recording / reproducing apparatus according to the first embodiment, and the details thereof will be given. Description is omitted.

That is, in the magneto-optical disk recording / reproducing apparatus according to the second embodiment, in the channel clock forming section 2, with respect to the phase of the basic clock divided by 24 by the 1/24 frequency dividing circuit 33. A delay circuit 45 which gives a predetermined delay of 1 clock or less, a basic clock divided by 24 from the 1/24 divider circuit 33, and a basic clock which has a predetermined delay given by the delay circuit 45 are C
It has a selector 46 which is selected by the control of the PU 40 and is supplied to the phase comparator 34.

In the channel clock forming section 2 having such a structure, the CPU 40 selects the basic clock from the delay circuit 45, which is delayed by a predetermined delay of 1 clock or less, in the recording mode. In the reproduction mode, the selector 45 is selectively controlled so as to select the undelayed basic clock directly supplied from the 1/24 frequency divider 33.

As a result, in the phase comparator 34, 1
It is possible to perform the above phase comparison with accuracy less than the clock,
A channel clock controlled with an accuracy of 1 clock or less can be supplied to the modulation circuit 6 or the demodulation circuit 11 via the output terminal 48 via the second VCO 36. Therefore, the recording start timing can be controlled with one clock or less, and the recording of the recording data can be started from a more accurate position.

Next, in the magneto-optical disk recording / reproducing apparatus according to the second embodiment, the 1/24 frequency dividing circuit 3 is used.
The delay circuit 45 applies a fixed delay to the basic clock from No. 3, but it is good that the timing of the phase comparison can be controlled with an accuracy of 1 clock or less, but this is a fixed accuracy. Therefore, in the magneto-optical disk recording / reproducing apparatus according to the third embodiment of the present invention, the channel clock forming section 2 is configured as shown in FIG. Was made to be selective. In the description of the magneto-optical disk recording / reproducing apparatus according to the third embodiment, the same reference numerals are given to the portions showing the same operations as those of the magneto-optical disk recording / reproducing apparatus according to the first embodiment, and the details thereof will be given. Description is omitted.

That is, in the magneto-optical disk recording / reproducing apparatus according to the third embodiment, in the channel clock forming section 2, the phase error detection supplied from the D / A converter 30 via the phase compensating circuit 31 is detected. A ring oscillator 5 that generates basic clocks of a plurality of phases according to a signal
0 and the CPU 4 from among the basic clocks of the plurality of phases
The basic clock of the phase selected by 0
The selector 51 supplied to the frequency dividing circuit 33 and the phase of the synchronization clear signal from the phase comparison timing generator 41 are corrected based on the phase of the basic clock selected by the selector 51, and the 1/24 frequency dividing circuit is obtained. And a correction circuit 52 for supplying the signal to the reference numeral 33.

As shown in FIG. 9, the ring oscillator 50 is composed of a total of 21 stages of 1st to 21st inverters 61. Inverted output and non-inverted output are taken out from each inverter 61, and the selector 51 is respectively provided. It is designed to be supplied to. The inverter 61 is the D / A
A basic clock having a frequency corresponding to the voltage value of the phase error detection data supplied from the converter 30 via the phase compensation circuit 31 is oscillated. Therefore, according to this configuration, the basic clock having a frequency corresponding to the phase error detection data is delayed by each of the 21-stage inverters 61, and the inverter 61 outputs an inverted output and a non-inverted output. In order to take it out, the basic clock having a total of 42 kinds of phases is supplied to the selector 51. The selector 51 is supplied with each basic clock having 42 types of phases within one clock width.

The selector 51 includes the inverters 6
It has a two-stage configuration having first and second selectors 62 and 63 to which the basic clocks of 1 to 42 types of phases are respectively supplied. The CPU 40 supplies, for example, 6-bit selection control data to the first selector 62 via the input terminal 60a, so that among the 42 types of phase basic clocks supplied to the first selector 62. A basic clock having a phase to be supplied to the A / D converter 20, the counter 26, the intra-segment counter 28, etc. is selected. The basic clock selected by the first selector 62 is supplied to the A / D converter 20 via the output terminal 64b.
And the counter 26 and the intra-segment counter 28. As a result, the servo pattern is detected as described above based on the basic clock having the selected phase.

In this way, the first selector 62
Since the basic clock selected in step 1 is used for detecting the servo pattern, etc., if the phase of the basic clock selected by the first selector 62 is too out of phase, the detection of the servo pattern will be hindered. Therefore, the first selector 62 selects the basic clock having the optimum phase from the first six basic clocks among the 42 types of basic clocks having the phases and supplies the selected basic clock to the A / D converter 20 and the like. I am trying.

The second selector 63, as shown in FIG. 10, has a D flip-flop 66 and an AND gate 67 to which the 42 types of phase basic clocks are respectively supplied.
The 0th to 41st selection circuits having a 42-stage configuration, and one basic clock selected by the CPU 40 from the basic clocks from the selection circuits are output.
And an R gate 69.

Each D flip-flop 6 of each selection circuit
The clock input terminal of No. 6 is supplied with the basic clock supplied from each of the inverters 61 via the input terminal 68a, and the data input terminal is supplied with the selection control data from the CPU 40 via the input terminal 68b. . Also,
The basic clock supplied from the inverters 61 is supplied to the AND gates 67 of the selection circuits via the input terminals 68a. Therefore, the CPU 40
Supplies high-level selection control data to the selection circuit to which the basic clock of the desired phase is supplied via the input terminal 68b, so that the basic clock of the phase supplied to the selection circuit is OR gate 69. And output terminal 7
It will be output via 0. The basic clock of the phase selected by the CPU 40, which is output via the output terminal 70, is the correction circuit 52 and 1 / shown in FIG.
It is supplied to each of the 24 frequency divider circuits 33.

Next, in FIG. 8, the intra-segment counter 28 has its count value reset by the servo pattern detection data as shown in FIG. 11B, as shown in FIG. 11A. The basic clock selected by the first selector 62 is counted in 216 clock cycles as shown in FIG. Then, this count value is supplied to the phase comparison timing generator 41. The detection count value of the phase comparison timing generator 41 is set to "2" as described above in the recording mode. Therefore, when the count value from the intra-segment counter 28 becomes "2", the phase comparison timing generator 41 outputs a negative synchronization clear signal as shown in FIG. It is supplied to the 1/24 frequency divider circuit 33 via 52.

In the 1/24 frequency divider circuit 33, the count value is cleared by the synchronization clear signal, as shown in FIG.
The basic clock selected by the second selector 63 as shown in FIG. 2 is divided by 24, and the phase comparison signal as shown in FIG.

Further, the 1 / N frequency dividing circuit 37 supplies the channel clock as shown in FIG. 11 (k) supplied from the VCO 36 when the frequency dividing ratio is set to 24, for example. The frequency is divided by 24 as shown in j), and the phase comparison signal as shown in FIG.

The basic clock divided by 24 by the 1/24 frequency divider 33 is a basic clock selected from 42 basic clocks having 42 types of phases within one clock width. In the device 34, the phase comparison with the channel clock can be performed at a desired timing within one clock width. Therefore, the channel clock formed on the basis of the phase error signal formed in the phase comparator 34 can be made to have more accurate timing. Therefore, by supplying the channel clock from the VCO 36 to the modulation circuit 6 shown in FIG.
As shown in (m), the recording start timing or the reproduction start timing can be controlled within one clock width,
More accurate recording / reproducing of recorded data can be performed.

Since the synchronization clear signal generated by the phase comparison timing generator 41 as described above is formed by the counter value from the intra-segment counter 28, it is selected by the first selector 62. It can be said that it is formed based on the basic clock. On the other hand, the basic clock generated by the 1/24 frequency divider circuit 33 is generated based on the basic clock selected by the second selector 63. Therefore, if the count value of the 1/24 frequency divider circuit 33 is cleared directly by the synchronization clear signal from the phase comparison timing generator 41, the basic clock from the first selector 62 and the second selector 63 from Since the phases of the basic clocks are different, accurate timing control is hindered. Therefore, in the channel clock forming unit 2 of the magneto-optical disk recording / reproducing apparatus according to the third embodiment, the synchronization clear signal from the phase comparison timing generator 41 is corrected by the correction circuit 52 and the above-mentioned 1/24. It is supplied to the frequency dividing circuit 33.

That is, the correction circuit 52 has a configuration as shown in FIG. 12, and the synchronization clear signal from the phase comparison timing generator 41 receives the first and second signals via the input terminal 77. It is supplied to each data input terminal of the D flip-flops 71a and 71b. The input terminal 78 is connected to the clock input terminal of the first D flip-flop 71a.
The basic clock selected by the first selector 62, which is supplied via a, is supplied via an inverter 72. In addition, the second D flip-flop 71
The basic clock selected by the first selector 62 is supplied to the clock input terminal of b via the input terminal 78a.

Each of the D flip-flops 71a, 71b
Respectively re-form the synchronization clear signal based on the basic clock, and regenerate the synchronization clear signal with the first NAND gate 73.
a, 73b.

The determination circuit 76 is supplied via the input terminal 79 with the selection control data used when the second selector 63 from the CPU 40 selects the basic clock of the desired phase. The determination circuit 76 detects the phase of the basic clock selected by the second selector based on the selection control data, and when the delay amount of this phase is ½ basic clock (half clock) or more, , When the high level data is supplied to the first NAND gate 73a and the delay amount of the phase of the basic clock is equal to or less than the half clock, the second NAND gate 73
Supply high level data to b.

Accordingly, when the delay amount of the phase is equal to or more than the half clock, the first D flip-flop 7
The synchronization clear signal formed by 1a is the first NAND
When the delay amount of the phase is supplied to the third D flip-flop 75 via the gate 73a and the NOR gate 74 and the phase delay amount is equal to or less than the half clock, the synchronization clear signal formed by the second D flip-flop 71b is changed to the first value. 2 N
Third via the AND gate 73b and the NOR gate 74
Is supplied to the D flip-flop 75.

The basic clock selected by the second selector 63 is supplied to the clock input terminal of the third D flip-flop 75 via the input terminal 80. The third D flip-flop 75 uses the first D flip-flop 7 based on the basic clock.
1a or the phase of the synchronization clear signal supplied from the second D flip-flop 71b is corrected to the phase of the currently selected basic clock, which is divided into 1/24 minutes shown in FIG. 1 /
The count value of the 24 divider circuit 33 is cleared.

Specifically, the basic clock as shown in FIG. 13A is selected by the second selector 63,
When the delay amount of the basic clock is equal to or less than the half clock, the sync clear signal as shown in FIG. 7B supplied to the first D flip-flop 71a through the input terminal 77 is transmitted through the inverter 72. (D) based on the falling edge of the basic clock
The first NAND gate 73a whose phase is controlled as shown in FIG.
And NOR gate 74 to the third D flip-flop 75.

The third D flip-flop 75 outputs the phase-controlled synchronization clear signal based on the rising edge of the basic clock selected by the second selector 63 as shown in FIG. 13C. By controlling the phase, the synchronization clear signal is appropriately corrected and supplied to the 1/24 frequency divider 33 as shown in FIG.

Further, the second selector 63 shown in FIG.
When the basic clock as shown in FIG. 4 (a) is selected and the delay amount of the basic clock is equal to or more than the half clock, the second D flip-flop 71b is input through the input terminal 77.
The sync clear signal as shown in FIG. 7B supplied to the first terminal is phase-controlled as shown in FIG. 7D based on the rising edge of the basic clock supplied as it is through the input terminal 78. The second D flip-flop 7 via the NAND gate 73b and the NOR gate 74
5 is supplied.

The third D flip-flop 75 outputs the phase-controlled synchronization clear signal based on the rising edge of the basic clock selected by the second selector 63 as shown in FIG. 14C. By controlling the phase, the synchronization clear signal is appropriately corrected and supplied to the 1/24 frequency divider 33 as shown in FIG.

Thus, the phase of the synchronization clear signal can be corrected according to the phase of the channel clock selected at that time, and the 1/24 frequency divider circuit 3
The count value of 3 can be cleared at the timing according to the selected basic clock. Therefore, the phase comparator 34 can perform the phase comparison with the channel clock at a more accurate timing. Therefore, it is possible to record / reproduce the record data at a more accurate timing.

Further, since the basic clock having a desired phase is selected from the basic clocks having a plurality of phases formed by the ring oscillator 50, the time from the reproduction of the servo pattern to the detection of each apparatus is different. Even when variations occur, it is possible to select a basic clock having a phase according to the device, and it is possible to contribute to recording / reproducing of recorded data at the above-mentioned accurate timing.

In the description of each of the above embodiments, the servo pattern recorded on the magneto-optical disk 1 is composed of a pair of wobble pits WP deviated by a predetermined amount with respect to the recording track TR. However, this may be any pattern as long as it can be recognized as a servo pattern without such a configuration.

Further, the magneto-optical disk 1 on which the above-mentioned servo pattern is recorded is used, but this is, for example, an optical disk on which not only the above-mentioned servo pattern but also recording data is recorded by pits, or the above-mentioned servo pattern by magnetism. The formed magnetic disk (including hard disk) may be used.

In the magneto-optical disk 1, the recording / reproducing area is divided into 15 zones, and the intra-segment counter 28 has been described with specific numerical values such as 216 counting the basic clock. Is just an example, and it goes without saying that various modifications can be made without departing from the technical idea of the present invention.

[0136]

According to the recording / reproducing apparatus for a disk-shaped recording medium of the present invention, the servo pattern recorded on the disk-shaped recording medium is reproduced and then reproduced.
Even if it takes time for the signal to be supplied to the servo pattern detecting means, the recording is started earlier by this time, so that the recording can be accurately performed from the predetermined recording position on the disc-shaped recording medium. It is possible to start, and it is possible to prevent the inconvenience that the record information is recorded with a deviation from the predetermined recording position.

Further, since the delay means delays the basic clock from the basic clock forming means by a fixed amount of 1 basic clock or less, the recording / reproducing start timing is controlled with an accuracy of 1 basic clock or less. Therefore, more accurate recording / reproducing can be performed.

Alternatively, since the delay means delays the basic clock from the basic clock forming means by an arbitrary amount less than or equal to one basic clock, the recording / reproducing start timing is set to the resolution of the delay means. It can be controlled with accuracy, and more accurate recording and reproduction can be performed. In this case, after the servo pattern is reproduced, the reproduced servo pattern reproduction signal is
Even if there is a variation in each device during the time until it is supplied to the detection unit, it is possible to correct this and perform accurate recording / reproduction.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of a magneto-optical disk recording / reproducing apparatus to which a disk-shaped recording medium recording / reproducing apparatus of the present invention is applied.

FIG. 2 is a schematic diagram showing a state in which a recording / reproducing area of a magneto-optical disc used in the magneto-optical disc recording / reproducing apparatus is divided into a plurality of zones.

FIG. 3 is a schematic diagram showing an example of a servo pattern recorded on the magneto-optical disk.

FIG. 4 is a waveform diagram showing a reproduced waveform of the servo pattern.

FIG. 5 is a time chart for explaining the operation in the recording mode of the magneto-optical disk recording / reproducing apparatus according to the first embodiment.

FIG. 6 is a time chart for explaining the operation in the reproduction mode of the magneto-optical disk recording / reproducing apparatus according to the first embodiment.

FIG. 7 is a block diagram of a channel clock forming unit provided in a magneto-optical disk recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 8 is a block diagram of a channel clock forming unit provided in a magneto-optical disk recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 9 is a block diagram showing a specific configuration of a ring oscillator provided in a channel clock forming unit of the magneto-optical disc recording / reproducing apparatus according to the third embodiment.

FIG. 10 is a block diagram showing a specific configuration of a selector provided in a channel clock forming unit of the magneto-optical disc recording / reproducing apparatus according to the third embodiment.

FIG. 11 is a time chart for explaining the operation of the magneto-optical disc recording / reproducing apparatus according to the third embodiment.

FIG. 12 is a block diagram showing a specific configuration of a correction circuit provided in a channel clock forming unit of the magneto-optical disk recording / reproducing apparatus according to the third embodiment.

FIG. 13 is a time chart for explaining the operation of the correction circuit when the delay amount of the basic clock is equal to or less than a half clock.

FIG. 14 is a time chart for explaining the operation of the correction circuit when the delay amount of the basic clock is equal to or more than a half clock.

FIG. 15 is a block diagram of a conventional magneto-optical disk recording / reproducing apparatus.

FIG. 16 is a schematic diagram of a servo pattern recorded on a magneto-optical disk used in a conventional magneto-optical disk recording / reproducing apparatus.

FIG. 17 is a waveform diagram showing a reproduced waveform of the servo pattern.

FIG. 18 is a schematic diagram showing a recording / reproducing area of a magneto-optical disk used in the conventional magneto-optical disk recording / reproducing apparatus, which is divided into a plurality of zones.

[Explanation of symbols]

1 Magneto-optical disk 2-channel clock generator 3 reproduction system 4 recording system 5 Spindle motor 6 Modulation circuit 7 Magnetic head 8 drivers 9 Optical system 10 R / W amplifier 11 Demodulation circuit 20 A / D converter 21 Phase data formation circuit 22 Data latch circuit 23 Phase generator 24 pulse detector 25 Servo pattern detector 26 counter 27 Lock / Unlock detection circuit 28 segment counter 29 Timing generator 30 D / A converter 31 Phase compensation circuit 32 First Variable Voltage Oscillator (VCO) 33 1/24 divider circuit 34 Phase comparator 36 Second VCO 37 1 / N frequency divider 38 N division ratio setting circuit 39 Zone setting register 40 CPU 41 Phase comparison timing generator 42 Phase comparison timing generation register

Claims (4)

(57) [Claims] 1. A light for reproducing a servo pattern periodically recorded on a disk-shaped recording medium which is rotationally driven at a constant angular velocity.
Based on the academic system and the servo pattern reproduction signal reproduced above,
A servo pattern detecting means for detecting a loop, a basic clock forming means for forming a basic clock synchronized with the detection output of this servo pattern, and a basic clock forming means for reproducing the recorded information. Based on the detected output of the detected servo pattern, a reproduction timing control signal indicating a predetermined reproduction start timing is formed and output, and at the time of recording the recording information, the reproduction is performed based on the detected output of the servo pattern . The servo
The pattern reproduction signal is supplied to the servo pattern detection means.
The timing control means for forming and outputting the recording timing control signal for advancing the recording start timing by the time required for the recording start timing, and the basic clock forming means from the basic clock forming means according to the recording / reproducing position of the disc-shaped recording medium A channel clock having a phase-locked loop configuration in which the phase of the basic clock is variably controlled and the phase of the basic clock is variably controlled according to the reproduction timing control signal or the recording timing control signal and is output as a channel clock. A recording / reproducing apparatus for a disk-shaped recording medium, comprising: forming means; and recording / reproducing means for recording / reproducing recording information to / from the disk-shaped recording medium based on the channel clock from the channel clock forming means. 2. A channel clock is formed by selecting a delay means for delaying the basic clock from the basic clock forming means by a fixed amount of one basic clock or less and a basic clock from the basic clock forming means at the time of reproduction. 2. A recording / reproducing apparatus for a disk-shaped recording medium according to claim 1, further comprising: a selecting unit that supplies the basic clock from the delay unit and supplies the basic clock from the delay unit to the channel clock forming unit during recording. . 3. A delay means for delaying the basic clock from said basic clock forming means by an arbitrary amount of one basic clock or less and supplying it to said channel clock forming means. Recording / reproducing apparatus for disk-shaped recording medium. 4. The delay means selects from a ring oscillator that outputs a plurality of types of delays of one basic clock or less to the basic clock, and a plurality of basic clocks having a plurality of types of phases from the ring oscillator. 4. A recording / reproducing apparatus for a disk-shaped recording medium according to claim 3, further comprising: selecting means for selecting a basic clock having a desired phase and supplying it to the channel clock forming means.